Perception

Question 1

Briefly describe the visual pathway.

Answer 1

Eye -> Retina -> LGN -> Primary visual cortex

Question 2

What are ‘simple’ cells in V1 selective for?

Answer 2

Position on retina, orientation of edge/bar and size/width of bar.

Question 3

What are ‘complex ‘ cells in V1 selective for (in addition to ‘simple’ cell sensitivity)?

Answer 3

Movement within the receptive field.

Question 4

What are ‘complex ‘ cells in V1 selective for (in addition to ‘simple’ cell sensitivity)?

Answer 4

The length of the edge or bar - Must stop at one/both ends.

Question 5

How does V1 detect so many different shapes?

Answer 5

There are many different receptive fields, with different orientation, spatial scales and positions.

Question 6

What leads to a local virus defect?

Answer 6

Damage to V1.

Question 7

How is the V1 mapped?

Answer 7

On the cortex, with areas processing contours on particular regions of the retina.

Question 8

What is the catchphrase for Gestalt psychology?

Answer 8

“The whole is more than the sum of the parts.”

Question 9

Give the 5 Gestalt ‘grouping principles.’

Answer 9

Similarity, proximity, closure, good continuation and common fate.

Question 10

Which cells are selective for edges defined by good continuity and closure?

Answer 10

V2 cells

Question 11

Which ‘grouping principles’ are impaired by V2 damage?

Answer 11

Good continuity, closure and similarity (particularly colour).

Question 12

Give 6 examples of things which change an object’s image.

Answer 12

Distance, position, perspective view, orientation, lighting and occlusion of parts.

Question 13

Describe object agnosia.

Answer 13

The failure to recognise without any loss of intelligence or vision.

Question 14

Describe Marr’s model of recognition.

Answer 14

Edge filters use Gestalt grouping to separate segments and arrange them as cylinders to match 3D memorised models.

Question 15

Suggest a problem with Marr’s model of recognition.

Answer 15

Many objects are hard to recognise if upside down or rotated.

Question 16

Describe Biederman’s ‘Recognition by Components.’

Answer 16

Geon types and arrangement for each part of an object are determined and matched to a memorised description.

Question 17

Describe a problem with Biederman’s ‘Recognition by Components.’

Answer 17

It does not differentiate objects within classes.

Question 18

What do cells in the temporal cortex code for?

Answer 18

Shape, colour and texture.

Question 19

What can cause object agnosia?

Answer 19

Lesion of the temporal cortex.

Question 20

What is prosopagnosia?

Answer 20

Face agnosia, where individuals may recognise objects but cannot recognise individual faces.

Question 21

When does the right fusiform area become active?

Answer 21

When shown faces.

Question 22

When does the right occipitotemporal area become active?

Answer 22

When shown bodies.

Question 23

How do hypothetical Grandmother cells work?

Answer 23

They respond to one object only.

Question 24

(External/internal) features are more important for recognising unfamiliar faces.

Answer 24

External

Question 25

(External/internal) features are more important for recognising familiar faces.

Answer 25

Internal

Question 26

What does improved recognition of caricatures imply?

Answer 26

Faces are coded by their difference from average.

Question 27

What 6 basic emotions have universal interpretations?

Answer 27

Happiness, sadness, anger, fear, surprise and disgust.

Question 28

How do patients lacking the amygdala fail to reconfigure fear expressions?

Answer 28

They do not look at the eyes.

Question 29

What brain area is activated by expressions of disgust?

Answer 29

Insula cortex

Question 30

Which brain area is sensitive to both attractiveness and gaze direction?

Answer 30

Ventral thalamus

Question 31

Which brain area has increased activity based on smiling?

Answer 31

Orbito-frontal cortex

Question 32

What are some explanations for colour after effects?

Answer 32

Pigment bleaching, neuronal fatigue and opponent processing of colour.

Question 33

What explains brightness and colour contrast?

Answer 33

They are coded relative to the surround.

Question 34

What explains motion contrast?

Answer 34

Stationary objects appear to move in the opposite direction to moving ones.

Question 35

What is the Zöllner illusion?

Answer 35

Orientation contrast

Question 36

Briefly describe the stages of bottom-up processing.

Answer 36

Low level feature detectors -> Mid level pattern detectors -> High level object detectors

Question 37

Briefly describe the stages of top-down processing.

Answer 37

Memorised concepts -> High level object detectors -> Mid level patter man detectors

Question 38

What is the word superiority effect?

Answer 38

Detecting a letter is easier in the context of a word.

Question 39

What causes a 'target present' bias in a signal detection test?

Answer 39

When there is a reward for hits but no penalty for false alarms.

Question 40

What causes a 'target absent' bias in a signal detection test?

Answer 40

When there is no reward for hits but a sever penalty for false alarms.

Question 41

Give 4 factors that influence the attractiveness of a face.

Answer 41

Averageness, symmetry, sexual dimorphism and health.

Question 42

Give 3 factors that influence someone feeling attraction to a face.

Answer 42

Hormone levels, status and imprinting.

Question 43

Describe Gibson's theory of direct perception.

Answer 43

Visual information directly controls actions so that visual properties of objects 'afford' actions.

Question 44

What is ataxia?

Answer 44

Ability to recognise objects but not guide actions.

Question 45

When do mirror neurones discharge?

Answer 45

During execution, observation and sound of an action, and even when it can only be deduced.

Question 46

What is the motor theory of speech?

Answer 46

We simulate production of speech we hear.